A facile method of solution combustion was used to synthesize a new solid solution Bi 2Ce 2O 7. The structure was determined from powder X-ray diffraction (PXRD) and found to crystallize in the space group Fm3m with cell parameter a = 5.46936(9) Å. The particle sizes varied from 5 to 6 nm. The degradation of cationic dye malachite green (MG) was investigated under solar radiation as the band gap of the material is 2.34 eV. © 2012 The Royal Society of Chemistry.